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1.2 - THE CIRCULATORY
SYSTEM
1.2 - THE CIRCULATORY
SYSTEM
LEARNING OUTCOMESLEARNING
OUTCOMES• To state what a circulatory system is,
• To state the three components of circulatory system in humans
& animals• To state the medium of
transport humans & animals• To state the composition of
human blood• Explain the function of blood &
haemolymph in transport
CIRCULATORY SYSTEM
CIRCULATORY SYSTEM• The mass flow of fluid through the
tissues & organ of the organism.• The bodily system consisting of the heart,
blood vessels, and blood that circulates blood throughout the body, delivers
nutrients and other essential materials to cells, and removes waste products
• Allows for the transport & exchange of nutrients, oxygen & waste products.
• Also protecting the body against infection.• 3 main components : a medium
(blood), vessels (arteries, capillaries & veins) & a pump (heart).
Blood & Haemolymph
Blood & Haemolymph
• Blood – medium of transport in human & animals
• Transport O2, CO2, nutrients, hormones & waste products.
• Regulate the pH of body fluid, the body temperature & the water content
of cells.• Protects the body against diseases,
blood clots to protect the body against excessive blood loss following an
injury.
•Haemolymph – in many arthropods (such as insects) and
certain molluscs, fills in the entire body cavity (haemocoel).
• A circulating blood-like fluid with an open circulatory system
• Transport water, inorganic salts & organic compounds
• The haemolymph bathes the tissues & internal organ directly.
COMPOSITION OF HUMAN
BLOOD
COMPOSITION OF HUMAN
BLOODHUMAN BLOOD
BLOOD CELLS (45%)
PLASMA (55%)
PLATELETS• 2.5 mil/mm3
LEUCOCYTES• 7000 mil/mm3
ERYTHROCYTES• 5 mil/mm3 FIBRINOGEN SERUM
Granulocyte :-• Basophils• Neutrophils• Eosinophils
Agranulocytes :-• Monocytes
• Lymphocytes
2 main components of human blood
55% plasma 45% blood cells
1. Pale yellow liquid
2. 90% of water 10% of a variety of dissolved substances
> nutrient > mineral ions > antibodies > enzymes > hormones
1. Red blood cells
2. White blood cells
3. platelets
•Contain 5 million RBC in every millilitre of human blood
•Erythrocytes is shaped like a biconcave disc (thinner at the centre than at its edge) large TSA/V ratio for gaseous exchange
•7.5-8.0 µm in diameter•Has a thin plasma membrane•Small biconcave shape + thin flexible plasma membrane enable the RBC to squeeze through the narrow blood capillaries.
• Mature RBC have no nucleus more space to pack in haemoglobin (respiratory protein containing iron).
• Haemoglobin contains haem groups which gives the erythrocytes its red colour.
• The haem group contains an iron atom & is the site of O2 binding.
• Each blood cells contains about 250 million haemoglobin molecules. Each haemoglobin can combine with 4 O2
molecules oxyhaemoglobin• Lifespan of an erythrocytes is only 120 days destroyed by the phagocytes in
the liver & spleen.• Continuously produced by the bone
marrow of the long bones, ribs, skull & vertebrae.
• More than 2 million RBC are destroyed & replaced every second in the human
body.
Colourless & have a nucleus, not contain haemoglobinLarger than RBCClassified as either granular or granular6000 – 10000 WBC in every millilitre of blood.Do not have fix shape, can move by changing body shapeProduced in the bone marrow, some migrate to the thymus gland & others to lymph nodes during their growth & development stages.
LEUCOCYTESLEUCOCYTES
Granulocytes
Have granular cytoplasm & a lobed nucleus
• produced in bone marrow
• 72% leukocytes are granulocytes
Basophils : Secrete heparin to prevent blood clotting
Eosinophils : Help to control allergic responses
Neutrophils : Phagocytes granulocytes. They engulf foreign
material (bacteria) by phagocytosis & destroy them.
Agranulocytes
• relatively clear
cytoplasm & nucleus is not
lobed.
Monocytes : The largest of the leucocytes. Circulate in the
bloodstream for a few days body tissues to become phagocytic
macrophage
Lymphocytes : The smallest leucocytes. Important in the body’s
defence against pathogens. Some produce antibodies to aid in the
destruction of pathogens or neutralise the toxins
•Small irregular shaped cell fragments produced in the bone
marrow•Play an important role in
blood clotting to reduce blood loss & to prevent the entry of
pathogens through the wounds into the body.
•Each millilitre of blood contains about 250000 platelets., do not
have a nucleus.
• The pale yellow liquid part of the blood
CONTENT DESCRIPTIONWater •90% of plasma content.Plasma protein
• Albumin•Globulin – type of antibody
•Fibrinogen- helps blood clotting Mineral ions • sodium, potassium & chloride
Absorbed food
substances
• glucose, amino acids, cholesterol & other lipids
Waste products
Urea, CO2, uric acid, creatinine and a little ammonium ion.
Dissolved gases
O2, CO2 & Nitrogen
Hormones & enzymes
Insulin, adrenaline, ADH
• Blood serum – plasma from which fibrinogen & other clotting
factors have been removed
THANK YOUTHANK YOU
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